Computational and experimental insights into phase transformation and sensing performance

The integration of functional shape memory alloys into metallic matrices produced by additive manufacturing has remained largely unexplored. In this work, a superelastic NiTi wire was embedded within an AlSi10Mg matrix fabricated by Laser Powder Bed Fusion and investigated as an intrinsic strain sensor. Ex-situ tensile tests up to 6 % strain revealed a distinct resistivity response directly associated with the onset and progression of stress-induced martensitic transformation. When embedded, the wire's in-situ resistivity measurements up to 2.5 % strain reproduced the same transformation signature, confirming that matrix encapsulation preserved the sensing functionality. Real-time synchrotron X-ray diffraction identified the initiation of the B2→B19′ transformation at ∼1.0 % strain and tracked the evolution of the variant under interfacial constraints. Finite element analysis predicted localized stress amplification at the wire–matrix interface, in close agreement with experimentally observed strain thresholds. The combined experimental and computational results demonstrate the feasibility of embedding NiTi wires as strain sensors, offering high sensitivity, extended strain range, and enhanced stability compared to conventional gauges. These findings establish a foundation for multifunctional smart structures in aerospace, biomedical, or advanced manufacturing applications.